In the case of a single sliding body, such as a snowboard, this presents the problem that there is only one side edge that grips in the snow when making a turn so that only relatively small forces can be exerted on the snowboard by the snow, such that fast sharp turns are difficult to make.
When using a pair of skis there are of course two such edges so that this is less of a problem. Hereby the user has to be well trained to keep the skis parallel.
Various mechanisms are known to keep a number of skis parallel and/or to tilt them together, for example in U.S. Pat. No. 6,113,115, DE 3628111 and WO2010/136034. However, here the user always to make a tilting movement around a horizontal axis to make the skis tilt.
This is not always easy because either the lower legs of the user have to take up this tilting or the centre of gravity of the user is no longer above the skis so that an intrinsically unstable position is obtained.